1. Field of the Invention
The present invention generally relates to the field of pressurized containers. More particularly, the present invention relates to the field of pressurized containers used to store and re-pressurize tennis balls, racket balls, squash balls, basketballs, and the like.
2. Description of the Prior Art
Athletic balls used in games such as tennis, squash, racket ball, basketball, and the like are typically hollow, spherical in shape, and composed of rubber or a rubber-like material. These athletic balls are typically pressurized and, as such, will readily bounce off of a sports racket or the floor and walls of the court in or upon which the game is being played. Over time and through repetitive use, these athletic balls lose will gradually lose air through the process of osmosis which causes them to depressurize. When athletic balls depressurize, they soften and lose their resilience or, in more general terms, they lose their “bouce.” As a result, these athletic balls have a relatively short useful life and the user will eventually and continually have to replace them with newer, fresher athletic balls.
This problem of athletic balls losing pressure has been partially solved by sporting goods manufacturers who market these athletic balls in pressurized cans or containers. While stored under pressure, the athletic balls will not depressurize because the pressure in the can is equal to or greater than the pressure inside the ball. In fact, the athletic balls will not begin to depressurize until the storage container is opened and the athletic balls are put into play. The prior art has numerous examples of devices that use pressurized containers to slow down this depressurization or, in many cases, actually re-pressurize the athletic ball once it has been used.
For example, U.S. Pat. No. 4,019,629 issued to Dubner et al. (1977) discloses a pressurized tennis ball container comprised of a separate cap with a hand-pump and one or more externally-mounted valves attached thereto. The cap screws onto a cylindrical threaded collar surrounding the top edge of a standard tennis ball container. The invention disclosed by Dubner et al. is similar to several others in the prior art that contemplate placing all of the external fixtures (valves, gauges, connections, etc.) on a removable cap that is somehow attached to the rim located at the top of a standard tennis ball container.
Similarly, U.S. Pat. No. 4,428,478 issued to Hoffman (1984) discloses a self-sealing pump for use in sealing and pressurizing a container for tennis balls. This device, like the device disclosed by Dubner et al., contemplates a separate cap with a hand-pump and one or more externally mounted valves attached thereto. This cap also screws onto a cylindrical threaded collar placed around the top of a standard tennis ball container.
U.S. Pat. No. 4,450,667 issued to Fitzpatrick (1984) discloses an apparatus and method for rejuvenating worn or used balls by subjecting them to steam heat in a closed environment. This device uses an external source of heat to pressurize athletic balls as opposed to an attached air pump or air compressor to pressurize the container.
U.S. Pat. No. 5,002,196 issued to Bassili (1991) discloses a pressure vessel having a removable lid for storing objects under pressure. This invention was designed to accommodate the pressurization of numerous tennis balls in a single location trough the use of an electric air compressor attached to the pressure vessel. This invention permitted the user to pressurize a larger number of tennis balls than the three typically found in a standard, commercially distributed container. Bassili also disclosed a removable lid to form an airtight seal with the pressure vessel by means of an O-ring or PVC gasket.
U.S. Pat. No. 5,014,848 issued to Wild et al. (1991) discloses a portable device for storing multiple tennis balls under pressure. This device is similar to the pressurized ball containers disclosed by Dubner et al. and Hoffman in that it is constructed with a hand-pump physically attached to the exterior surface of the tennis ball container.
U.S. Pat. No. 5,311,988 issued to Bronson (1994) discloses a pressurizing cap that fits over a conventional tennis ball container. This portable, inexpensive device relies upon the downward movement of the cap to compress the air trapped inside to pressurize the tennis ball container; in essence, the cap acts as a piston to compress the air in the container.
U.S. Pat. No. 5,397,018 issued to Mader (1995) discloses a tennis ball handling system that has two storage systems. One storage system is quite complex and remains in a fixed location while the other, the player's storage container is much simpler in design and it is also portable. The player's storage container is comprised of a portable cylindrical container, a removable screw-on cap with input and relief valves placed thereon, and an external pressurizing source.
U.S. Pat. No. 5,615,596 issued to Issa (1997) discloses an inflated ball container and re-pressurizer that fit over the open end of a tennis ball container and forces compressed air into the closed container when the diaphragm on the cap is depressed. This device is quite similar in concept to the devices disclosed by Dubner et al. and Hoffman in that it uses a pressurizing source that is attached to the storage container.
U.S. Pat. No. 5,730,286 issued to Eska (1998) discloses a container with a pressure vessel for regenerating and storing tennis balls. Eska discloses a device comprised of a portable, cylindrical chamber, with a removable screw-on cap with valves integrated into the cover itself, and an input connection located in the base of the container. The device disclosed by Eska contemplates the use of a hand-pump attached to the tennis-ball container or an external source, such as an air compressor.
In another field, U.S. Pat. No. 5,469,979 issued to Chiou (1995) discloses an adjustable sealed can that uses an attached hand-pump to withdraw air from the container through a valve screwed into a threaded hole in the container's removable screw-on top.
Cumulatively, these devices have made significant headway in addressing the problem of athletic balls losing their bounce. Successive inventors have built upon the lessons learned by their predecessors so as to disclose improved pressurized containers that are portable, more affordable, and more durable. That said, there remain several issues and problems that have not been adequately addressed by the prior art, both individually and collectively. Specifically:
(1) Most, if not all, of the devices found in the prior art are complex in design and construction and are difficult and complicated to operate. This makes them expensive to manufacture which, in turn, makes them expensive for the consumer to purchase. Further, these complex designs typically give rise to increasingly larger numbers of breakable parts. The parts must be replaced or the user must purchase an entirely new device either of which represents a significant increase in their cost to the consumer.
(2) Most, if not all, of the devices found in the prior art contain or rely upon specially or uniquely designed or fabricated valves, fixtures, gauges, and other such attachments. This makes these devices expensive because these specially designed valves, fixtures, and gauges must be engineered and manufactured separately which adds significantly to the cost of such devices. These increased manufacturing costs are passed on to the consumer Further, these specially designed or fabricated attachments typically give rise to increasingly larger numbers of breakable parts which, again, increases the cost of the device to the consumer who must repair or replace the broken parts or purchase a new device altogether.
(3) Most, if not all, of the devices found in the prior art contain fixtures, valves, and the like attached to a removable cap that would fit over a pressurized container. Further, these fixtures and valves typically extend vertically and outward from the surface of these removable caps. Such a configuration subjects these fixtures, valves and the like to an increased risk of breaking, bending, snapping-off, misalignment, or other such damage as the cap is repeatedly taken off the container, set aside somewhere, and then replaced. Further still, the cap, as it is repeatedly removed, set down, and reattached, is at risk of being dropped, jarred, shaken, stepped on, or otherwise knocked around physically. Any of these actions could damage, misalign, distort, or otherwise render ineffective the attachments in or on this removable cap.
(4) Most of the devices found in the prior art contain fixtures, valves, and the like attached to a removable cap that would fit over a pressurized container. This removable cap could be easily misplaced or stolen which would require the user to incur the expense of purchasing another such device or doing without.
(5) Most of the devices found in the prior a have some type of pumping mechanism physically attached to the athletic ball container. Having a pressurizing device such as a hand-pump physically attached to these devices adds to their complexity and expense of its design, manufacture, and operation which, in turn, makes them more expensive to the consumer. Further, the use of an attached hand-pump requires the user to move the piston or pump handle up and down in the vicinity of the container, making it awkward and difficult to move. Finally, the use of an attached hand-pump often requires a customized can to accommodate the hand-pump.
(6) Most of the devices disclosed in the prior art are limited in size to fit over a standard tennis ball container or to accommodate only tennis balls. Further, they are typically limited to use with containers made of a lightweight, malleable metal which, as previously mentioned, is often susceptible to deformation or other such damage leading to leakage.
(7) Most, if not all, of the devices disclosed in the prior art require the use of gaskets or other such pliable, elastic materials to effect an airtight seal between the lid and the athletic ball container. These gaskets will eventually deteriorate and fail. As such, the gaskets have to be replaced which ultimately adds to the costs endured by the consumer who uses these devices.
(8) Most, if not all, of the devices disclosed by the prior art have fixtures, valves, and the like which are exposed to dirt, dust, water intrusion, and other such contaminants that negatively impact the operability of such fixtures and valves and that will eventually cause them to deteriorate. Such deterioration renders the device ineffective or useless and thereby requires the user to repair or replace the damaged valves, purchase another such device, or do without.
(9) Most, if not all, of the devices disclosed by the prior art contemplate the use of a standard, commercially distributed tennis ball canister that contains only three tennis balls. They cannot accommodate more than three tennis balls and they cannot accommodate other types of athletic balls.
(10) Most, if not all, of the devices disclosed by the prior art contemplate a device designed to pressurize tennis balls. As such, their design and construction precludes their use in pressurizing other types of athletic balls.
(11) Most, if not all, of the devices disclosed by the prior art contemplate the use of materials that have a relatively low compression strength which makes them susceptible to damage when an attached hand-pump is used to pressurize the device.
(12) Most, if not all, of the devices disclosed by the prior art are limited to either an external source of compressed air or an attached source of compressed air (such as a hand-pump).
(13) Most, if not all, of the devices disclosed by the prior art are unstable and tend to tip over because of the numerous attachments, valves, and the like positioned near the top of the device.
(14) Many of the devices disclosed by the prior art are bulky, cumbersome, and difficult, if not impossible, to carry from place to place.